Cell Bio
1. a. Describe in detail how a direct DNA repair mechanism works.
b. Can you think of a way in which you could inhibit this repair mechanism in bacteria that have been exposed to UV radiation?

2. For each of the following, give a brief description:
a. DNA exonuclease
b. AP site
c. DNA ligase
d. post replication repair

3. a. What is cancer? Include in your answer a description of oncogenes.
b. describe how a mutated DNA repair gene could lead to a cancer.
c. If a mutation occurs in a gene in a skin cell, describe two possible outcomes for the future of that cell.

4. a. What is a retrovirus?
b. How can a retrovirus cause the transformation of a normal cell into a cancer cell?
c. What is a transforming retrovirus and how does it cause cancer?

5. a. What is a transposon? In you answer include two distinguishing features of a transposon.
b. What is meant by conservative and replicate transfer?
c. Briefly describe the mechanism of action of the Ds and Ac transposons as discovered in maize by McClintock.